If you eat crab without knowing that you are pregnant, if you do not have vaginal bleeding, back pain, abdominal pain and other manifestations of pre-eclampsia, you do not need to worry too much, regular routine pregnancy tests and timely supplementation of folic acid in the first trimester of pregnancy will do. Crab has the function and healing effect of activating blood, and taking too much of it may induce the phenomenon of miscarriage. This food is a high-protein food, which may cause gastrointestinal reactions, resulting in nausea, vomiting, diarrhea and other symptoms, not all of which will appear. After eating crabs, you should drink more water and observe more. If you experience abdominal pain, vaginal bleeding and other symptoms of miscarriage, you need to choose birth control measures in time. Take bed rest for a few weeks, avoid mental tension, cooperate with intramuscular progesterone injection for fetal preservation treatment, and recheck after a week.